Personality traits predict hierarchy rank in male rainbowfish social groups

Abstract

Personality traits are becoming increasingly important in explaining adaptive individual differences in animal behaviour and probably represent a leading edge of the evolutionary process. Despite the newfound interest in animal personality among behavioural ecologists, fewstudies have investigated the link between personality traits and fitness measures. We examined this link using male rainbowfish, Melanotaenia duboulayi, as a model species and found that a range of personality traits (aggression, activity and boldness) covaried with a male's position in a hierarchy, which is directly related to reproductive success in this and many other species. Dominant fish were more aggressive, active, bold and also significantly larger than subordinate fish. Moreover, we found strong correlations between activity levels and boldness suggesting that selection may act on a suite of traits in concert (sensu behavioural syndromes). When taken together with previous research, our results suggest that the activityeboldness syndrome is likely to be domain specific. We suggest that multiple trait correlations may be generated by high levels of competition (e.g. sexual selection) in addition to predation pressure as identified by previous studies.

Social Learning in Fishes

“…Male rainbowfish, Melanotaenia duboulayi (Castelnau), in contrast seem to pay little attention to whether a female is observing male-male contests or not. In the presence of a female observer, jousting males made fewer charges but the number of bites, chases and lateral displays remained the same as when a female was absent (Colleter & Brown 2011). Thus, the focus of research has swiftly switched from dyads to the examination of communication networks.…”

Personality Traits and Behaviour

“…Furthermore, there is no clear relationship between aggressiveness and social dominance (e.g. Bakker 1986;Francis 1988;Colleter & Brown 2011), and dominance and growth rate can also be unrelated (e.g. Harwood et al 2003).…”

“…However, they can involve behavioural variability linked with competitive ability, resource utilisation and life-history traits (e.g. Biro & Stamps 2008;Colleter & Brown 2011).…”

Animal personality as a cause and consequence of contest behaviour

“…Having a short recovery time may mean that more stings can be landed on the opponent, which increases the chance of victory in escalated fights. Similarly, in contests over dominance status in rainbowfish, Melanotaenia duboulayi [18], zebra finches, Taeniopygia guttata [19], and domestic fowl, Gallus gallus domesticus [5], dominant individuals are consistently more proactive when not fighting and more aggressive during fights. Thus, personality traits such as boldness not only covary with aggressiveness but also, in many cases, with RHP itself.…”